So the first backup i made worked fine. It uploaded the files correctly but now i get this error every time.

http://pastebin.com/fH570Dpt

Any ideas?

No idea, look in your sftp server log, if it has one.
Server thrown generic error on directory create.

It shoudn't send a failure in such case. Try another sftp server software.

In sftp log i got this

sftp-server[691]: mkdir name "/asw/" mode 0777
sftp-server[691]: sent status Failure

So maybe the error is because the directory already exists?

Do you have any suggestion? I was just using default from centos, installed vsftp but same result.

No idea, i used windows sftp server software when testing.
Will try to workaround that somehow.

If you could just check if the main directory exists before executing the mkdir it would probably work, i didn't look at the code so just guessing. In my case they are the default i believe /asw and /asw/backups
Because the first backup always works perfectly when those directories don't exist yet.

Yea, that's what i will do when i have time.